cups fails to print, debug log lines are blank

I'm attempting to print to a Dell 2350dn using the Dell ppd. It once worked and now doesn't, but I use this printer infrequently and don't know what happened in the interim.

The cups error log has:

E [07/Feb/2014:16:11:53 -0800] [Job 140] Job stopped due to filter errors; please consult the error_log file for details.
D [07/Feb/2014:16:11:53 -0800] [Job 140] The following messages were recorded from 16:11:53 to 16:11:53
D [07/Feb/2014:16:11:53 -0800]
---- (above line repeated apx 40 times) ----
D [07/Feb/2014:16:11:53 -0800] [Job 140] End of messages
D [07/Feb/2014:16:11:53 -0800] [Job 140] printer-state=3(idle)
D [07/Feb/2014:16:11:53 -0800] [Job 140] printer-state-message="Filter failed"
D [07/Feb/2014:16:11:53 -0800] [Job 140] printer-state-reasons=none

Notice that the debug message is blank. There is no indication of which filter failed or why (other than "Filter failed" in error_log and in the print.

I have attempted to reinstall the printer several times with no change.

One of the actions in the interim was to install a set of packages I installed to support a Canon MF4890dw (cndrvcups-ufr2-us and cndrvcups-common). I removed (purged) both of those, but the situation is unchanged.

Any suggestions?

Also posted to http://stackoverflow.com/questions/21640325/ .